During biological sampling of hydrothermal vents on the East Pacific Rise, the manned submersible 'Nautile' caught the first female of the endemic cephalopod Vulcanoctopus hydrothermalis. The specimen caught at the vent site Gromit (21 degrees 33 66'S, 114 degrees 17 98'W at 2832 m depth) is described here in detail and an amended diagnosis of the species proposed. The external morphology, measurements and internal structure resemble that Of males of this species. One of the most remarkable characters is the lack of spermathecae and the absence of apical filaments in the oocytes to provide a site for sperm storage. It is suggested that some species of the genera Benthoctopus and Bathypolypus would be the most suitable octopod ancestor of V. hydrothermalis.